PDBsum entry 2vn5

Cell adhesion

PDB id: 2vn5

Contents

Protein chains

142 a.a. *

56 a.a. *

Metals

_CA ×4

Waters ×293

* Residue conservation analysis

PDB id:

2vn5

Name:

Cell adhesion

Title:

The clostridium cellulolyticum dockerin displays a dual binding mode for its cohesin partner

Structure:

Scaffolding protein. Chain: a, c. Fragment: residues 277-427. Synonym: cohesin. Engineered: yes. Endoglucanase a. Chain: b, d. Fragment: residues 410-475. Synonym: dockerin, endo-1,4-beta-glucanase a, egcca, cellulase a.

Source:

Clostridium cellulolyticum. Organism_taxid: 1521. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.182 R-free: 0.234

Authors:

B.A.Pinheiro,J.A.M.Prates,M.R.Proctor,H.J.Gilbert,G.J.Davies, V.A.Money,C.Martinez-Fleites,E.A.Bayer,C.M.G.A.Fontes,H.P.Fierobe

Key ref:

B.A.Pinheiro et al. (2008). The Clostridium cellulolyticum Dockerin Displays a Dual Binding Mode for Its Cohesin Partner. J Biol Chem, 283, 18422-18430. PubMed id: 18445585 DOI: 10.1074/jbc.M801533200

Date:

31-Jan-08 Release date: 20-May-08

Protein chains

Q45996  (Q45996_9FIRM) -  Scaffolding protein from Ruminiclostridium cellulolyticum

Seq: 1546 a.a.

Struc: 142 a.a.

Protein chains

P17901  (GUNA_CLOCE) -  Endoglucanase A from Ruminiclostridium cellulolyticum (strain ATCC 35319 / DSM 5812 / JCM 6584 / H10)

Seq: 475 a.a.

Struc: 56 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chains B, D: E.C.3.2.1.4 - cellulase.
• Reaction: Endohydrolysis of 1,4-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.

DOI no: 10.1074/jbc.M801533200

J Biol Chem 283:18422-18430 (2008)

PubMed id: 18445585

The Clostridium cellulolyticum Dockerin Displays a Dual Binding Mode for Its Cohesin Partner.

B.A.Pinheiro, M.R.Proctor, C.Martinez-Fleites, J.A.Prates, V.A.Money, G.J.Davies, E.A.Bayer, C.M.Fontesm, H.P.Fierobe, H.J.Gilbert.

ABSTRACT

The plant cell wall degrading apparatus of anaerobic bacteria includes a large multienzyme complex termed the "cellulosome." The complex assembles through the interaction of enzyme-derived dockerin modules with the multiple cohesin modules of the noncatalytic scaffolding protein. Here we report the crystal structure of the Clostridium cellulolyticum cohesin-dockerin complex in two distinct orientations. The data show that the dockerin displays structural symmetry reflected by the presence of two essentially identical cohesin binding surfaces. In one binding mode, visualized through the A16S/L17T dockerin mutant, the C-terminal helix makes extensive interactions with its cohesin partner. In the other binding mode observed through the A47S/F48T dockerin variant, the dockerin is reoriented by 180 degrees and interacts with the cohesin primarily through the N-terminal helix. Apolar interactions dominate cohesin-dockerin recognition that is centered around a hydrophobic pocket on the surface of the cohesin, formed by Leu-87 and Leu-89, which is occupied, in the two binding modes, by the dockerin residues Phe-19 and Leu-50, respectively. Despite the structural similarity between the C. cellulolyticum and Clostridium thermocellum cohesins and dockerins, there is no cross-specificity between the protein partners from the two organisms. The crystal structure of the C. cellulolyticum complex shows that organism-specific recognition between the protomers is dictated by apolar interactions primarily between only two residues, Leu-17 in the dockerin and the cohesin amino acid Ala-129. The biological significance of the plasticity in dockerin-cohesin recognition, observed here in C. cellulolyticum and reported previously in C. thermocellum, is discussed.

Selected figure(s)

Figure 2.
FIGURE 2. The three-dimensional structures of the C. cellulolyticum cohesin-dockerin complexes. a depicts the structure of Coh-DocA16S/L17T with the dockerin color-ramped from N terminus (blue) to C terminus (red) and the cohesin in pale brown. In this complex the hydrophobic residues Phe-48 and Ala-47 dominate the hydrophobic contribution of the dockerin, and these residues are shown as ball-and-stick. Ca^2+ ions are shown as shaded spheres. b shows the CohDocA47S/F48T complex, similarly colored. Here Leu-17 and Ala-16 of the dockerin form the basis of the hydrophobic surface of the dockerin. c depicts an overlap of the two binding modes showing the very high degree of overall similarity reflecting the internal 2-fold symmetry of the dockerin itself (see text). A47S/F48T is shown in blue and A16S/L17T in yellow.

Figure 4.
FIGURE 4. Overlap of the C. cellulolyticum and C. thermocellum cohesin-dockerin complexes in both binding modes highlighting the key recognition signature. A, C. cellulolyticum Coh-Doc A16S/L17T mutant complex (light green) is overlaid with the equivalent C. thermocellum cohesin-dockerin (wild type) complex (crimson) (PDB 1OHZ [PDB] ). B depicts the C. cellulolyticum Coh-Doc A47S/F48T mutant complex (yellow) overlaid with the equivalent C. thermocellum cohesin-dockerin S45A/T46A complex (pale blue) (PDB 2CCL).

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2008, 283, 18422-18430) copyright 2008.

Figures were selected by an automated process.